The instant invention relates to a process for automatic evacuation, on a movable conveyor belt, of wound bobbins of a spinning, winding or twisting machine with work stations on both sides thereof, the conveyor belt being positioned in the longitudinal center of the machine so that a random replacement of bobbins can be carried out. A device for carrying out the process is also provided.
DE-OS 39 12 513 describes the arrangement of one single conveyor belt in the longitudinal center of the machine. Bobbins are placed on the conveyor belt from both sides of the machine after a bobbin replacement. When the machine initiates a bobbin replacement on the opposite side after drop-off of a bobbin of the conveyor belt, the automatic travelling carriage checks the bobbin occupancy of the conveyor belt in front of that spinning station to determine the state of either "occupied" or "free". The automatic travelling carriage utilizes sensors functioning without physical contact for this verification, the sensors being designed in the form of reflection light barriers. If the location on the conveyor belt is already occupied due to the drop-off of a bobbin, the automatic travelling carriage recognizes by means of the sensors what the state of the drop-off location on the belt is and transmits a control signal which causes the conveyor belt to continue moving in increments until a free location for drop-off at the location concerned is available and the initiated bobbin replacement can be carried out.
The solution described has the disadvantage that the automatic travelling carriage travelling in front of the spinning stations must be equipped additionally with sensing devices in order to recognize whether a drop-off location is free on the conveyor belt. The reflection light barriers are furthermore subject to malfunctions due to dirt caused by flying fibers and require periodic maintenance for that reason. It is another advantage that the bobbins produced in a random sequence are dropped off on the conveyor belt and are removed without any information concerning quality and work station origin being transmitted to downstream conveying and processing machines. DE-OS 37 31 125 describes a similar solution.
Other state-of-the-art solutions provide the bobbins during bobbin removal additionally with machine-readable codes (DE-OS 39 12 488) or labels (EP 342 527). The technical effort required to read the codes and to affix labels on the yarn body or on the bobbin former is, however, a disadvantage.